If you ever needed a good reason to eat more mushrooms, here it is: adding mushrooms to your diet can increase the intake of key micronutrients most of us are actually lacking (such as vitamin D) without affecting the intake of calories, a new study found. The benefits were found on both the diets of children and adults and are in line with a growing literature on the benefits of mushrooms.

More mushrooms, please

The finding is especially relevant in the current COVID-19 pandemic. Studies have shown low levels of vitamin D among patients diagnosed with the novel coronavirus, and there seems to be a correlation between vitamin D deficiency and severe COVID-19 cases, although there are no conclusive findings just yet.

Mushrooms, the bodies of filamentous fungi that grow above the ground, have long been a part of the human diet and used as both foods and medicine. They provide many of the same nutritional benefits as vegetables, as well as attributes commonly found in meat, beans, and grains (such as a high number of proteins). They’re biologically distinct from both plants and animals.

A group of US researchers modelled the nutritional impact of adding a serving of mushrooms, using the dietary intake data from the US National Health and Nutrition Examination Survey (NHANES) — which includes at a sample of 10,000 adults and children every two years. The focused on the surveys from 2011 to 2016 for the study.

In a previous study, they had already found that mushroom intake was associated with higher intakes of several key nutrients and better diet quality. However, the intake was low at 2.3 g per day per capita or 20.6 g per day among consumers in the US. Now, they wanted to look at what would happen if consumers started eating more mushrooms. Unsurprisingly, the more mushrooms people consumed, the better they scored for key nutrients.

Adding a serving of 84 grams of mushroom to the diet increased several nutrients that are often lacking from our diets, the researchers found. This was true for the white, crimini, portabella, and oyster mushrooms. An increase in fiber (5%-6%), copper (24%-32%), phosphorus (6%), potassium (12%-14%), selenium (13%-14%) and zinc (5%-6%) and riboflavin (13%-15%) was reported.

The study also showed that a serving of UV-light mushrooms (mushrooms exposed to UV light) decreased population insufficiency for vitamin D from 95.3% to 52.8% for the age group 9-18 years and from 94.9% to 63.6% for the age group 19+ years. Similar to humans, mushrooms naturally produce vitamin D following exposure to sunlight or a sunlamp.

“This research validated what we already knew that adding mushrooms to your plate is an effective way to reach the dietary goals,” Mary Jo Feeney, nutrition research coordinator to the Mushroom Council, said in a statement. “Data from surveys are used to assess nutritional status and its association with health promotion and disease prevention and assist with formulation of national standards.”

Studies showed over the years similar large behind mushrooms. Mushroom eaters (people who ate two portions of mushrooms per week) performed better in brain tests and had overall faster brain processing speed, a 2019 study showed. Also, in 2017, a study found mushrooms have high levels of ergothioneine and glutathione, two compounds with important antioxidant properties.

The study was published in the journal Food Science & Nutrition.